Could he be the same person as William McGlencey?
He was mustered into service on 19 September 1861 (1). He served as a private, initially in company K (1).
He was transferred on 24 December 1861 to company E (1).
1 Bates, Samuel Penniman. History of Pennsylvania volunteers, 1861-5. Harrisburg: B. Singerly, state printer, 1869-71. 5 volumes. 'Ninety-first regiment', volume 3, pages 186-233.' (In the roster) (William McGinsey)